The invention concerns an embossing station for an embossing apparatus which is provided for transferring a transfer layer of an embossing film on to an element to be embossed upon, in particular a flat element to be embossed upon which is stable in respect of shape, wherein the embossing station has two support rollers which are spaced from each other and which are in mutually axis-parallel relationship and at least one deflection roller spaced from the support rollers and in axis-parallel relationship with the support rollers, around which an embossing belt is deflected, wherein an embossing section of the embossing belt is determined by the support rollers.
An embossing station of that kind is known from DE 202 05 662 U1. In order to positively influence the quality of the join of the transfer layer of the embossing film to the element to be embossed upon, in particular the flat element to be embossed upon which is stable in respect of shape, it is proposed therein that at least one stabilisation roller which bears against the embossing belt is provided between the two support rollers which define the embossing section of the embossing belt. Those stabilisation rollers are of a smaller diameter than the support rollers in order to be able to provide a suitable number of stabilisation rollers between the two support rollers and in that way to increase the number of line contacts. As a consequence of the smaller diameter the rotary speed of the stabilisation rollers is correspondingly increased. That increased rotary speed of the stabilisation rollers is accompanied by a reduction in the service life of the bearings of the stabilisation rollers.
DE 101 59 662 A1 discloses a deflection roller for an embossing machine, with which an increase in output, that is to say an increase in the machine speed of the embossing machine, in other words an increase in the rotary speed of the roller, is possible by securing to a bar which is fixed with respect to the machine, a porous air-permeable bar sleeve on which a roller sleeve is mounted, wherein the roller bar has a compressed air passage for supplying the bar sleeve with compressed air which is provided to form an air cushion between the bar sleeve and the roller sleeve. That air cushion affords a substantial reduction in the frictional losses of that known deflection roller.
An apparatus for transferring a decoration from an embossing film on to a web of material is known for example from EP 0 521 414 B1.
A heatable and coolable roller with an almost friction-free mounting arrangement is described in DE 44 16 421 A1. That known roller serves for transporting material in web form and for providing for temperature control thereof, wherein a fluid is used for supporting a roller casing which rotates on a stationary cylindrical core, the fluid flowing predominantly in the peripheral direction between the roller casing and the roller core. That fluid can be used at the same time for temperature control of the roller casing.
An air-supported roller is also known for example from U.S. Pat. No. 3,349,462 A.
As, in an embossing station of the kind set forth in the opening part of this specification, the quality of the join of the transfer layer of the embossing film to the element to be embossed upon, in particular the flat element which is stable in respect of shape, as well as the embossing speed are dependent to a high degree on the number of line contacts along the embossing section between the embossing belt and the flat element to be embossed upon, the requirement involved is that of providing for an improvement in the quality and an increase in the embossing speed by increasing the number of line contacts.